Vapor deposition processes for tantalum carbide nitride materials

ABSTRACT

Embodiments of the invention generally provide methods for depositing and compositions of tantalum carbide nitride materials. The methods include deposition processes that form predetermined compositions of the tantalum carbide nitride material by controlling the deposition temperature and the flow rate of a nitrogen-containing gas during a vapor deposition process, including thermal decomposition, CVD, pulsed-CVD, or ALD. In one embodiment, a method for forming a tantalum-containing material on a substrate is provided which includes heating the substrate to a temperature within a process chamber, and exposing the substrate to a nitrogen-containing gas and a process gas containing a tantalum precursor gas while depositing a tantalum carbide nitride material on the substrate. The method further provides that the tantalum carbide nitride material is crystalline and contains interstitial carbon and elemental carbon having an interstitial/elemental carbon atomic ratio of greater than 1, such as about 2, 3, 4, or greater.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 11/860,952, filed Sep. 25, 2007, which is hereinincorporated by reference. This application is related to U.S. patentapplication Ser. No. 11/860,945, filed Sep. 25, 2007, now issued as U.S.Pat. No. 7,585,762, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention generally relate to electronic deviceprocessing, and more particularly, to vapor deposition processes fortantalum-containing materials and the compositions of thetantalum-containing materials, such as tantalum carbide nitridematerials.

2. Description of the Related Art

The electronic device industry and the semiconductor industry continueto strive for larger production yields while increasing the uniformityof layers deposited on substrates having increasingly larger surfaceareas. These same factors in combination with new materials also providehigher integration of circuits per unit area on the substrate. Ascircuit integration increases, the need for greater uniformity andprocess control regarding layer characteristics rises.

Several areas of fabrication that are constantly improving include theformation of metal gate electrodes and the deposition of contact barrierlayers. Gate electrodes have often been made with silicon basedmaterials, but more frequently are made with metallic materials, such astungsten or cobalt. However, the materials used for gate electrodes havelacked accessible or tunable electronic properties by varying thecompositions of the contained materials. While tantalum materials havebeen used as barrier layers, tantalum materials have only been scarcelyused for the formation of metal gate electrodes, despite the variety ofelectronic characteristics available from tantalum materials.

Formation of tantalum-containing barrier layers, such as tantalum,tantalum nitride, and other tantalum materials, in multi-levelintegrated circuits poses many challenges to process control,particularly with respect to contact formation. Contacts are formed bydepositing conductive interconnect material in an opening (e.g., via) onthe surface of insulating material disposed between two spaced-apartconductive layers. Copper, tungsten, and aluminum are the most popularconductive interconnect materials, but may diffuse into neighboringlayers, such as dielectric layers. The resulting and undesirablepresence of these metals causes dielectric layers to become conductiveand ultimate device failure. Therefore, barrier materials are used tocontrol metal diffusion into neighboring materials.

Barrier layers formed from sputtered tantalum and reactive sputteredtantalum nitride have demonstrated properties suitable for use tocontrol metal diffusion. Exemplary properties include high conductivity,high thermal stability, and resistance to diffusion of foreign atoms.Physical vapor deposition (PVD) processes are used to deposit tantalummaterials as gate electrodes or in features of small size (e.g., about90 nm wide) and high aspect ratios of about 5:1. However, it is believedthat PVD processes may have reached a limit at this size and aspectratio. Also, the variety of compositions for tantalum materials is verylimited when using a PVD process.

Attempts have been made to use traditional tantalum precursors found inchemical vapor deposition (CVD) or atomic layer deposition (ALD)processes to deposit tantalum materials. Multiple CVD and ALD processesare anticipated to be used in the next generation technology of 45 nmwide features having aspect ratios of about 10:1 or greater. Also, ALDprocesses more easily deposit tantalum materials on features containingundercuts than does PVD processes. Formation of tantalum-containingfilms from CVD or ALD processes using TaCl₅ as a precursor may requireas many as three treatment cycles using various radial based chemistries(e.g., atomic hydrogen or atomic nitrogen) to form tantalum materials.Processes using TaCl₅ may also suffer from chlorine contaminants withinthe tantalum material. While metal-organic tantalum precursors may beused to form tantalum materials containing no chlorine contaminants, thedeposited materials may suffer with the undesirable characteristic of ahigh carbon content.

Therefore, there is a need for a process to deposit tantalum-containingmaterials, such as tantalum carbide nitride, on a substrate, includingas a metal gate electrode as well as a barrier layer, while controllingprocess parameters in order to form predetermined compositions havingselect electronic properties.

SUMMARY OF THE INVENTION

Embodiments of the invention generally provide methods for depositing atantalum-containing material, such as a tantalum carbide nitridematerial, onto a substrate, as well as for compositions of the tantalumcarbide nitride material. The methods include deposition processes thatform predetermined compositions of the tantalum carbide nitride materialby controlling the deposition temperature and the flow rate of anitrogen-containing gas during a vapor deposition process. Thedeposition process may include thermal decomposition processes, chemicalvapor deposition (CVD) processes, pulsed CVD processes, atomic layerdeposition (ALD) processes, as well as plasma enhanced (PE) processes,such as PE-CVD and PE-ALD.

In one embodiment, a method for forming a tantalum-containing materialon a substrate is provided which includes heating a substrate to atemperature within a process chamber, and exposing the substrate to anitrogen-containing gas and a process gas containing a tantalumprecursor gas while depositing a tantalum carbide nitride material onthe substrate. The method further provides that the tantalum carbidenitride material is crystalline and contains interstitial carbon andelemental carbon having an interstitial/elemental carbon atomic ratio ofabout 2 or greater, in some examples, about 3 or greater, and in otherexamples, about 4 or greater.

In another embodiment, a method for forming a tantalum-containingmaterial on a substrate is provided which includes heating a substrateto a predetermined temperature within a process chamber, and exposingthe substrate to a nitrogen-containing gas and a tantalum precursor gaswhile depositing a tantalum carbide nitride material on the substrate,and the tantalum carbide nitride material has the chemical formula ofTaC_(x)N_(y), wherein x is within a range from about 0.20 to about 0.50and y is within a range from about 0.20 to about 0.55. In anotherexample, x may be within a range from about 0.25 to about 0.40 and y iswithin a range from about 0.40 to about 0.50. Also, the tantalum carbidenitride material may have a sheet resistance within a range from about1×10⁴ Ω/sq to about 1×10⁶ Ω/sq.

Embodiments are provided in which the flow rate of thenitrogen-containing gas is adjusted to obtain the interstitial/elementalcarbon atomic ratio. For example, the flow rate of thenitrogen-containing gas may be adjusted to about 1,500 sccm or less,such as within a range from about 100 sccm to about 1,000 sccm. In someexamples, the nitrogen-containing gas and the process gas containing thetantalum precursor gas are exposed to the substrate at a gaseous flowrate ratio of at least about 1:1. Other examples provide that thegaseous flow rate ratio is at least about 3:1 or 5:1. The temperature ofthe substrate may be within a range from about 250° C. to about 600° C.,preferably, from about 350° C. to about 550° C., and more preferably,from about 400° C. to about 500° C. In one example, thenitrogen-containing gas contains ammonia. In other embodiments, thenitrogen-containing gas may contain amines or hydrazines.

In one specific example, a method for forming a tantalum-containingmaterial on a substrate is provided which includes heating a substrateto a temperature within a range from about 400° C. to about 500° C., andexposing the substrate to a nitrogen-containing gas and a tantalumprecursor gas comprising tertbutylimido-tris(ethylmethylamido)tantalum(TBTEMT) while depositing a tantalum carbide nitride material on thesubstrate, wherein the tantalum carbide nitride material is crystallineand contains an interstitial/elemental carbon atomic ratio of about 2 orgreater.

The tantalum precursor gas may contain an alkylamido tantalum compound,and may contain a carrier gas. The alkylamido tantalum compound may betertbutylimido-tris(ethylmethylamido)tantalum,tertbutylimido-tris(diethylamido)tantalum (TBTDEAT),tertbutylimido-tris(dimethylamido)tantalum (TBTDMAT),tertiaryamylimido-tris(dimethylamido)tantalum (TAIMATA),tertiaryamylimido-tris(diethylamido)tantalum,tertiaryamylimido-tris(methylethylamido)tantalum,pentakis(ethylmethylamido)tantalum (PEMAT),pentakis(diethylamido)tantalum (PDEAT), pentakis(dimethylamido)tantalum(PDMAT), plasmas thereof, derivatives thereof, or combinations thereof.In many examples, the alkylamido tantalum compound istertbutylimido-tris(ethylmethylamido)tantalum. In some embodiments, theprocess gas contains ammonia, nitrogen gas (N₂), hydrogen gas (H₂),plasmas thereof, derivatives thereof, or combinations thereof. In otherembodiments, the process gas may further contain a hydrocarbon gas tohelp regulate the carbon concentration. The hydrocarbon gas may bemethane, ethane, propane, butane, ethene, acetylene, butene, butyne,plasmas thereof, derivatives thereof, or combinations thereof.

In another embodiment, a composition of a tantalum carbide nitridematerial is provided which includes a chemical formula of TaC_(x)N_(y),wherein x is within a range from about 0.20 to about 0.50 and y iswithin a range from about 0.20 to about 0.55, an interstitial/elementalcarbon atomic ratio of about 2 or greater, and a crystalline structure.In some examples, the composition of the tantalum carbide nitridematerial provides that x is within a range from about 0.25 to about 0.40and y is within a range from about 0.30 to about 0.50 or in otherexamples, x is within a range from about 0.30 to about 0.40 and y iswithin a range from about 0.35 to about 0.50. In other examples, thecomposition of the tantalum carbide nitride material provides that theinterstitial/elemental carbon atomic ratio is about 3, 4 or greaterwithin the tantalum carbide nitride material. The tantalum carbidenitride material may have a sheet resistance within a range from about1×10⁴ Ω/sq to about 1×10⁶ Ω/sq. In some examples, the tantalum carbidenitride material may contain silicon or boron.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the inventioncan be understood in detail, a more particular description of theinvention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates a flow diagram showing a method of depositing atantalum carbide nitride material in accordance with embodimentsdescribed herein;

FIGS. 2A-2B depict cross-sectional views of substrates containingtantalum carbide nitride materials used as gate electrodes in accordancewith embodiments described herein; and

FIG. 3 depicts a cross-sectional view of another substrate containing atantalum carbide nitride material used as a barrier layer in accordancewith other embodiments described herein.

DETAILED DESCRIPTION

Embodiments of the invention provide a deposition process for depositinga tantalum-containing material, namely, a tantalum carbide nitridematerial, onto a substrate. The composition of the tantalum carbidenitride material may be controlled by adjusting the flow rate of anitrogen-containing gas during the deposition process. Also, byadjusting the temperature of the substrate, the composition of thetantalum carbide nitride material may be controlled during thedeposition process. The deposition process includes thermaldecomposition processes, chemical vapor deposition (CVD) processes,pulsed CVD processes, atomic layer deposition (ALD) processes, as wellas plasma enhanced (PE) processes, such as PE-CVD and PE-ALD.

In one example, the deposition process employs an alkylamido tantalumcompound as the tantalum precursor, such astertbutylimido-tris(ethylmethylamido)tantalum (TBTEMT) and ammonia asthe nitrogen-containing gas. In one embodiment, the deposited tantalumcarbide nitride material may have the chemical formula of TaC_(x)N_(y),wherein x is within a range from about 0.20 to about 0.50 and y iswithin a range from about 0.20 to about 0.55, an interstitial/elementalcarbon atomic ratio of about 2 or greater, and a crystalline structure.In some examples, the composition of the tantalum carbide nitridematerial provides that x is within a range from about 0.25 to about 0.40and y is within a range from about 0.40 to about 0.50. In otherexamples, the composition of the tantalum carbide nitride materialprovides that the interstitial/elemental carbon atomic ratio is about 3,4 or greater within the tantalum carbide nitride material.

FIG. 1 illustrates a flow chart depicting process 100 that may be usedto form a tantalum carbide nitride material. During step 102, asubstrate is heated to an initial deposition temperature within aprocess chamber. The substrate is subsequently exposed to anitrogen-containing gas (e.g., ammonia) that has an initial flow rate atstep 104. The tantalum carbide nitride material is deposited on thesubstrate while the nitrogen-containing gas is being exposed to thesubstrate during step 106. The tantalum carbide nitride material may bedeposited by a deposition process, such as thermal decomposition, CVD,pulsed-CVD, PE-CVD, ALD, PE-ALD, or derivatives thereof during step 106.At step 108, if the desired composition of the tantalum carbide nitridematerial is not achieved, then the process continues to step 110, wherethe adjustments are made to deposition temperature and/or the flow rateof the nitrogen-containing gas before proceeding back to step 106.However, if the desired composition is achieved, then the processcontinues to step 112. At step 112, if the desired thickness of thetantalum carbide nitride material is not achieved, then the processproceeds back to step 106. However, process 100 is over after achievingthe desired thickness of the tantalum carbide nitride material.

In step 102, a substrate is positioned within a process chamber andheated to an initial deposition chamber. The substrate may be heated toa temperature within a range from about 250° C. to about 600° C.,preferably, from about 350° C. to about 525° C., and more preferably,from about 400° C. to about 500° C. The process chamber has a controlledenvironment that is pressurized within a range from about 1 mTorr toabout 100 Torr, preferably, from about 1 Torr to about 10 Torr, and morepreferably, from about 2 Torr to about 5 Torr.

In step 104, the substrate is exposed to a nitrogen-containing gas thathas an initial flow rate. The nitrogen-containing gas may be used todeposit tantalum-containing materials, such as tantalum carbide nitridematerials. A nitrogen-containing gas or nitrogen precursor may include,ammonia (NH₃), hydrazine (N₂H₄), methyl hydrazine ((CH₃)HN₂H₂), dimethylhydrazine ((CH₃)₂N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine(C₆H₅N₂H₃), other hydrazine derivatives, amines, a nitrogen plasmasource (e.g., N₂, N₂/H₂, NH₃, or N₂H₄ plasmas), 2,2′-azotertbutane((CH₃)₆C₂N₂), organic or alkyl azides, such as methylazide (CH₃N₃),ethylazide (C₂H₅N₃), trimethylsilylazide (Me₃SiN₃), inorganic azides(e.g., NaN₃ or Cp₂CoN₃), and other suitable nitrogen sources. Radicalnitrogen compounds can be produced by heat, hot-wires and/or plasma,such as N₃, N₂, N, NH, or NH₂. In many examples, the nitrogen-containinggas contains ammonia. The nitrogen-containing gas may have a flow ratewithin a range from about 50 sccm to about 2,000 sccm, preferably, fromabout 100 sccm to about 1,500 sccm. In various examples, thenitrogen-containing gas may have a flow rate of about 100 sccm, 500sccm, 1,000 sccm or 1,500 sccm.

In step 106, the tantalum carbide nitride material is deposited on thesubstrate while the nitrogen-containing gas is being exposed to thesubstrate. During step 106, the tantalum carbide nitride material may bedeposited by a thermal decomposition process, a CVD process, apulsed-CVD process, a PE-CVD process, an ALD process, a PE-ALD process,or derivatives thereof.

In one embodiment, the tantalum carbide nitride material may bedeposited by exposing a substrate to a tantalum precursor gas formed byvaporizing the precursor TBTEMT. “TBTEMT” is used herein to describetertiary-butylimido-tris(ethylmethylamido)tantalum with the chemicalformula (^(t)BuN)Ta(NEtMe)₃, wherein ^(t)Bu is the tertiarybutly group(C₄H₉— or (CH₃)₃C—). A tantalum precursor gas may be formed by heating aTBTEMT precursor in a vaporizer, a bubbler, or an ampoule to atemperature of at least 50° C., preferably, to a temperature within arange from about 65° C. to about 90° C. A carrier gas (e.g., N₂ or Ar)is flown across or bubbled through the heated TBTEMT to form a tantalumprecursor gas.

An important precursor characteristic is to have a favorable vaporpressure. Deposition precursors may have gas, liquid or solid states atambient temperature and pressure. However, within the process chamber,precursors may be volatilized as gas. Precursors are usually heatedprior to delivery into the process chamber.

Although TBTEMT is one of the tantalum precursors that may be utilizedduring the deposition process in step 106, other tantalum precursors maybe heated to form tantalum precursor gases and used to deposit tantalumcarbide nitride materials as described herein. Tantalum precursors maycontain ligands such as alkylamidos, alkylimidos, cyclopentadienyls,halides, alkyls, alkoxides, or combinations thereof. Alkylamido tantalumcompounds used as tantalum precursors include (RR′N)₅Ta, where R or R′are independently hydrogen or an alkyl group, such as methyl, ethyl,propyl, butyl, or pentyl (amyl). Alkylimido tantalum compounds used astantalum precursors include alkylimido, tris-alkylamido tantalumcompounds, such as (R″N)(R′RN)₃Ta, where R, R′, or R″ are independentlyhydrogen or an alkyl group, such as methyl, ethyl, propyl, butyl, orpentyl. Specific tantalum precursors may include (^(t)AmylN)Ta(NMe₂)₃(TAIMATA), (^(t)AmylN)Ta(NEt₂)₃, (^(t)AmylN)Ta(NMeEt)₃,(^(t)BuN)Ta(NMe₂)₃ (TBTMT), (^(t)BuN)Ta(NEt₂)₃ (TBTET),(^(t)BuN)Ta(NEtMe)₃, (Et₂N)₅Ta (PDEAT), (Me₂N)₅Ta (PDMAT), (EtMeN)₅Ta(PEMAT), derivatives thereof. In many examples, the tantalum precursorcontains an amylimido compound, such as TBTEMT or TAIMATA during theformation or deposition of the tantalum carbide nitride material bythermal decomposition, CVD, pulsed-CVD, PE-CVD, ALD, or PE-ALD.“TAIMATA” is used herein to describe the liquid precursortertiaryamylimido-tris(dimethylamido)tantalum with the chemical formula(^(t)AmylN)Ta(NMe₂)₃, wherein ^(t)Amyl is the tertiaryamyl group (C₅H₁₁—or CH₃CH₂C(CH₃)₂—). The substrate may be exposed to a process gas thatincludes the tantalum precursor gas and a carrier gas. Herein, thecarrier gas and/or the purge gas may be argon, nitrogen, hydrogen,helium, forming gas (N₂/H₂), or combinations thereof.

Reducing agents and other reactive gases may be used to deposittantalum-containing materials within the deposition process during step106. In one embodiment, the tantalum-containing materials are thetantalum carbide nitride materials. However, in other embodiments, thetantalum-containing materials may contain silicon, boron, phosphorous,hydrogen, and other elements, as well as carbon and nitrogen. To achievea predetermined concentration of carbon in a depositedtantalum-containing material, additional carbon-containing compounds orcarbon precursors may be incorporated within the deposition processduring step 106. Carbon precursors may include methane, ethane, ethene,ethyne, propane, propene, propyne, butane, hexane, heptane, octane,nonane, decane, derivatives thereof, or combinations thereof.

Silicon-containing compounds or silicon precursors may be used todeposit tantalum-containing materials, such as tantalum silicide carbidenitride, tantalum silicide nitride, tantalum silicide carbide, ortantalum silicide. Silicon precursors include silanes and organosilanes.Silanes include silane (SiH₄) and higher silanes with the empiricalformula Si_(X)H_((2x+2)), such as disilane (Si₂H₆), trisilane (Si₃H₈),and tetrasilane (Si₄H₁₀), as well as others. Organosilanes includecompounds with the empirical formula R_(y)Si_(x)H_((2x+2−y)), where R isindependently methyl, ethyl, propyl or butyl, such as methylsilane((CH₃)SiH₃), dimethylsilane ((CH₃)₂SiH₂), ethylsilane ((CH₃CH₂)SiH₃),methyldisilane ((CH₃)Si₂H₅), dimethyldisilane ((CH₃)₂Si₂H₄) andhexamethyldisilane ((CH₃)₆Si₂). Exemplary silicon precursors includesilane, disilane, or methylsilane.

Boron-containing compounds or boron precursors may be used to deposittantalum-containing materials, such as tantalum boride carbide nitride,tantalum boride nitride, tantalum boride carbide, or tantalum boride.Boron precursors include boranes and organoboranes, which include borane(BH₃), diborane (B₂H₆), triborane (B₃H₈), tetraborane (B₄H₁₀),trimethylborane ((CH₃)₃B), triethylborane ((CH₃CH₂)₃B), or derivativesthereof. Exemplary boron precursors include diborane andtrimethylborane.

The composition of the tantalum carbide nitride material is determinedduring step 108 prior to the advancing to either step 110 or step 112.If the desired composition has not been obtained, process 100 proceedsto step 110 to adjust the particular process perimeters (e.g.,deposition temperature and/or flow rate of nitrogen-containing gas) inorder to achieve the desired composition. Alternatively, once theprocess perimeters are calibrated to obtain the desired composition ofthe tantalum carbide nitride material, process 100 progresses to step112.

In one embodiment, the tantalum carbide nitride material may bedeposited having a crystalline structure, such that two forms of carbonare incorporated within the tantalum carbide nitride material. Thecrystalline tantalum carbide nitride may have interstitial carbon, whichis covalently bonded to tantalum and nitrogen atoms, and isinterstitially positioned within at lattice sites of the crystallinestructure. The crystalline tantalum carbide nitride may also haveelemental carbon, which is physically incorporated (not covalentlybonded) to tantalum and nitrogen atoms, and is positioned outside if theat lattice sites of the crystalline structure.

Embodiments provide that the tantalum carbide nitride material may bedeposited having an interstitial/elemental carbon atomic ratio of about2 or greater. In some examples, the composition of the tantalum carbidenitride material provides that the interstitial/elemental carbon atomicratio is about 3, 4, or greater within the tantalum carbide nitridematerial. Also, the carbon and nitrogen concentrations may be varied sothat the tantalum carbide nitride material has a sheet resistance withina range from about 1×10⁴ Ω/sq to about 1×10⁶ Ω/sq.

In another embodiment, the tantalum carbide nitride material is formedor deposited with a chemical formula of TaC_(x)N_(y), wherein x iswithin a range from about 0.20 to about 0.50 and y is within a rangefrom about 0.20 to about 0.55. In some examples, x may be within a rangefrom about 0.25 to about 0.40 and y may be within a range from about0.40 to about 0.50.

During step 110, the deposition temperature, as well as the flow rate ofa nitrogen-containing gas may be adjusted in order to obtain the desiredcomposition of the tantalum carbide nitride material. Thereafter, thedeposition process in step 106 is repeated to form the tantalum carbidenitride material. The deposition temperature may be adjusted during thedeposition process, such as thermal decomposition, CVD processes, or ALDprocesses. The deposition temperature may be increased in order to lowerthe carbon concentration within the tantalum carbide nitride material.Alternatively, the deposition temperature may be lowered in order toincrease the carbon concentration within the tantalum carbide nitridematerial. In one embodiment, the temperature of the substrate or thesubstrate pedestal during step 106 may be within a range from about 250°C. to about 600° C., preferably, from about 350° C. to about 550° C.,and more preferably, from about 400° C. to about 500° C.

In another embodiment, the flow rate of the nitrogen-containing gas mayalso be adjusted to obtain the desired composition of the tantalumcarbide nitride material, such as a specific interstitial/elementalcarbon atomic ratio. The nitrogen-containing gas is administered duringthe deposition process, such as thermal decomposition, CVD processes, orALD processes. The flow rate of the nitrogen-containing gas may beadjusted to about 4,000 sccm or less, such as within a range from about100 sccm to about 4,000 sccm, preferably, from about 300 sccm to about3,000 sccm, and more preferably, from about 1,000 sccm to about 2,000sccm. The flow rate of the tantalum precursor gas may be adjusted toabout 1,000 sccm or less, such as within a range from about 50 sccm toabout 2,000 sccm, preferably, from about 100 sccm to about 1,000 sccm,and more preferably, from about 300 sccm to about 700 sccm.

The flow rate of the nitrogen-containing gas relative to the flow rateof the tantalum precursor gas may have a gaseous flow rate ratio ofabout 1:1, 2:1, 3:1, 4:1, 5:1, or higher. The gaseous flow rate ratiomay be increased in order to lower the carbon concentration within thetantalum carbide nitride material. Alternatively, the gaseous flow rateratio may be lowered in order to increase the carbon concentrationwithin the tantalum carbide nitride material. The tantalum precursor gascontains a vaporized tantalum precursor and usually contains a carriergas. The carrier gas may be argon, nitrogen, hydrogen, helium, forminggas, or combinations thereof. In one example, the substrate is exposedto a nitrogen-containing gas of ammonia having a flow rate of about1,250 sccm and a tantalum precursor gas of TBTEMT and argon having aflow rate of about 500 sccm during a thermal decomposition processhaving a gaseous flow rate ratio of about 2.5:1. In another example, thesubstrate is exposed to a nitrogen-containing gas of ammonia having aflow rate of about 1,500 sccm and a tantalum precursor gas of PDMAT andargon having a flow rate of about 500 sccm during a thermaldecomposition process having a gaseous flow rate ratio of about 3:1.

The thickness of the tantalum carbide nitride material may be determinedduring step 112. If the desired thickness has not been obtained, process100 reverts back to the deposition process in step 106 in order toachieve the desired thickness. Process 100 is stopped once the desiredthickness of the tantalum carbide nitride material has been formed onthe substrate. The overall thickness of the tantalum carbide nitridematerial is dependent on the specific requirements of the fabricationapplication. For example, the tantalum carbide nitride material may bedeposited to form a tantalum-containing gate electrode that has athickness within a range from about 10 Å to about 1,000 Å, preferably,from about 40 Å to about 200 Å. In another example, the tantalum carbidenitride material may be deposited to form a tantalum-containing barrierlayer that has a thickness within a range from about 3 Å to about 200 Å,preferably, from about 5 Å to about 100 Å, and more preferably, fromabout 10 Å to about 50 Å.

In one embodiment, FIG. 2A depicts tantalum-containing gate electrode210 containing a tantalum carbide nitride material deposited by methodsdescribed herein on substrate 200 a, which may be used in a Logicapplication. Substrate 200 a contains source layer 204 a and drain layer204 b deposited or formed on layer 202, which may be the substratesurface or a dielectric layer disposed thereon. In one example, sourcelayer 204 a and drain layer 204 b may be formed by implanting ions intolayer 202. The segments of source layer 204 a and drain layer 204 b arebridged by tantalum-containing gate electrode 210 formed on gateinsulting layer 206. An off-set layer or spacer 208 may be deposited onboth sides of tantalum-containing gate electrode 210. Gate insultinglayer 206 may contain a dielectric material such as hafnium oxide,hafnium silicate, hafnium silicon oxynitride, aluminates thereof, orderivatives thereof. Spacer 208 may contain silicon nitride, siliconoxynitride, derivatives thereof, or combinations thereof.

In another embodiment, FIG. 2B depicts tantalum-containing gateelectrode 210 containing a tantalum carbide nitride material depositedby methods described herein on substrate 200 b, which may be used in aFlash application. Substrate 200 b may share most of the features assubstrate 200 a, but also contains tantalum-containing gate electrode214, a gate control layer, deposited on isolation layer 212 which isdisposed on tantalum-containing gate electrode 210. Tantalum-containinggate electrode 214 may contain a tantalum carbide nitride materialdeposited by methods described herein. Isolation layer 212 may containan oxynitride, such as an oxide-nitride (ON) layered material or anoxide-nitride-oxide (ONO) layered material, a silicon nitride (SiN)layered material, or a silicide, such as tantalum silicide.

The tantalum carbide nitride material contained withintantalum-containing gate electrodes 210 or 214 may be formed ordeposited by a thermal decomposition process, a CVD process, apulsed-CVD process, a PE-CVD process, an ALD process, a PE-ALD process,or derivatives thereof. In some examples, a tantalum precursor thatcontains ligands such as alkylamidos and/or alkylamidos is used duringthe deposition process along with a nitrogen-containing gas. In oneexample, the deposition process utilizes TBTEMT as the tantalumprecursor and ammonia as the nitrogen-containing gas. The tantalumcarbide nitride material may be deposited to form tantalum-containinggate electrodes 210 or 214 having a thickness within a range from about10 Å to about 1,000 Å, preferably, from about 40 Å to about 200 Å.

In one example, the tantalum carbide nitride material has a crystallinestructure, such that the interstitial carbon and the elemental carbonhave an interstitial/elemental carbon atomic ratio of about 2 orgreater, preferably, about 3 or greater, and more preferably, about 4 orgreater within tantalum-containing gate electrodes 210 and 214. Thetantalum carbide nitride material may be deposited having a desiredcomposition by adjusting the nitrogen-containing gas flow rate or thetemperature of substrate 200 a during the deposition process. In oneexample, the tantalum carbide nitride material is formed with a chemicalformula of TaC_(x)N_(y), wherein x is within a range from about 0.20 toabout 0.50 and y is within a range from about 0.20 to about 0.55,preferably, x may be within a range from about 0.25 to about 0.40 and ymay be within a range from about 0.40 to about 0.50.

Tantalum-containing gate electrodes 210 or 214 may each have a variedcomposition to better control the work function, such as the workfunction of tantalum-containing gate electrode 210 between source layer204 a and drain layer. Tantalum-containing gate electrodes 210 and 214contain tantalum, carbon, nitrogen and optionally may contain silicon,boron, phosphorus, or combinations thereof. In many examples,tantalum-containing gate electrodes 210 or 214 contain tantalum carbidenitride with a sheet resistance within a range from about 1×10⁴ Ω/sq toabout 1×10⁶ Ω/sq. However, the work function of tantalum-containing gateelectrodes 210 or 214 may be adjusted to be less resistive by increasingthe nitrogen concentration and/or decreasing the carbon concentrationrelative to the tantalum concentration. In one example,tantalum-containing gate electrodes 210 or 214 contains tantalum carbidenitride with a sheet resistance of greater than about 1×10⁵ Ω/sq,preferably, about 1×10⁶ Ω/sq or greater. Alternatively, the workfunction of tantalum-containing gate electrodes 210 or 214 may beadjusted to be more resistive by decreasing the nitrogen concentrationand/or increasing the carbon concentration relative to the tantalumconcentration. In another example, tantalum-containing gate electrodes210 or 214 contains tantalum carbide nitride with a sheet resistance ofless than about 1×10⁶ Ω/sq, preferably, about 1×10⁴ Ω/sq or less.

In another embodiment, FIG. 3 depicts substrate 300 having an exemplarystructure upon which a tantalum carbide nitride material may bedeposited as tantalum-containing barrier layer 320. Substrate 300contains lower layer 302 that may be one or more layers and dielectriclayer 304 disposed thereon. Via 310 may be formed within dielectriclayer 304 by etching techniques or dielectric layer 304 may be depositedforming via 310. Via 310 extends through dielectric layer 304 to lowerlayer 302. Via 310 contains bottom surface 312 and wall surfaces 314.The field of substrate 300 extends across upper surface 316 ofdielectric layer 304.

Tantalum-containing barrier layer 320 contains a tantalum carbidenitride material may be deposited or formed on substrate 300 byemploying the deposition processes described herein, such as thermaldecomposition, CVD, pulsed-CVD, PE-CVD, ALD, or PE-ALD. The tantalumcarbide nitride material may be deposited to form tantalum-containingbarrier layer 320 having a thickness within a range from about 3 Å toabout 200 Å, preferably, from about 5 Å to about 100 Å, and morepreferably, from about 10 Å to about 50 Å.

Tantalum-containing barrier layer 320 may be directly deposited on uppersurface 316, as depicted in FIG. 3. Alternatively, upper surface 316 maybe pre-treated or have one or multiple layers deposited thereon, priorto the deposition of tantalum-containing barrier layer 320 (not shown).For example, an adhesion layer or a nucleation layer may be depositedbetween upper surface 316 and tantalum-containing barrier layer 320.Also, additional barrier layers, nucleation layers, or seed layers, maybe deposited onto tantalum-containing barrier layer 320 prior todepositing metal layer 322 (not shown). An adhesion layer, a nucleationlayer, a seed layer, or an additional barrier layer may containtitanium, tantalum, tungsten, cobalt, ruthenium, nitrides thereof,silicides thereof, or alloys thereof and may be formed by a depositionprocess such as ALD, CVD, or PVD. Tantalum-containing barrier layer 320may serve as a seed layer to promote the formation of metal layer 322using, for example, electroplating or ALD techniques. Importantcharacteristics that tantalum-containing barrier layer 320 shoulddemonstrate include good step coverage, thickness uniformity, highelectrical conductivity, and ability to prohibit copper diffusion.

In one example, tantalum-containing barrier layer 320 is formed fromtantalum carbide nitride material by sequentially exposing substrate 300to a tantalum precursor and at least another precursor during an ALDprocess. Although not required, tantalum-containing barrier layer 320may contain monolayers of multiple compounds, such as tantalum carbidenitride, tantalum carbide nitride, and tantalum metal.Tantalum-containing barrier layer 320 conforms to the profile of via 310so as to cover bottom surface 312 and wall surface 314, as well asacross upper surface 316 of dielectric layer 304.

Metal layer 322 fills via 310 while being deposited overtantalum-containing barrier layer 320. Metal layer 322 may contain aconductive metal that includes copper, tungsten, aluminum, tantalum,titanium, ruthenium, silver, alloys thereof, or combinations thereof.The deposition process used to form metal layer 322 may include CVD,PVD, electroless plating, electroplating, or combinations thereof. Also,metal layer 322 may include a combination of layers made by variousdeposition processes, such as a seed layer formed by an ALD process anda bulk layer or fill layer by a CVD process.

In one example, metal layer 322 contains a copper-containing seed layerdeposited by PVD, electroless plating, or electroplating and acopper-containing bulk layer deposited by CVD, electroless plating, orelectroplating. In another example, metal layer 322 contains aruthenium-containing seed layer deposited by ALD, PVD, electrolessplating, or electroplating and a copper-containing bulk layer depositedby CVD, electroless plating, or electroplating. In another example,metal layer 322 contains a tungsten-containing seed layer deposited byALD, CVD, or PVD and a tungsten-containing bulk layer deposited by CVD.

In an alternative embodiment, TBTEMT may be used as a tantalum precursorto form other ternary tantalum-containing materials, such as tantalumsilicon nitride, tantalum boron nitride, tantalum phosphorous nitride,tantalum oxynitride or tantalum silicate. A more detailed description ofa process to form ternary or quaternary elemental tantalum-containingmaterials is described in commonly assigned U.S. Pat. No. 7,081,271,which is incorporated herein in its entirety by reference.

In other examples, metal gate applications for tantalum carbide nitridematerial may be deposited by deposition processes described herein. Thedeposition processes preferably utilize TBTEMT as a tantalum precursorgas. The gate layer may contain a gate material such as siliconoxynitride, hafnium oxide, aluminum oxide or combinations thereof. Atantalum carbide nitride materials or a tantalum silicon nitridematerial is deposited on the gate layer by the vapor depositionprocesses described herein. Generally, the tantalum carbide nitridematerial is deposited on a gate layer with a thickness within a rangefrom about 20 Å to about 200 Å, preferably, about 40 Å. Subsequently, ametal-containing layer is deposited on the tantalum carbide nitridematerial. Metal-containing layers may contain titanium, titaniumnitride, tungsten, tantalum, ruthenium or combinations thereof and aredeposited by CVD, ALD, PVD, electrochemical plating, or electrolessplating processes. In one example, the metal-containing layer istitanium nitride deposited by a CVD process, an ALD process, or a PVDprocess. In another example, the metal-containing layer is tungstendeposited by a CVD process. In another example, the metal-containinglayer is tantalum deposited by a PVD process or an ALD process usingTBTEMT as described herein. In another example, the metal-containinglayer is ruthenium deposited by an ALD process.

A detailed description for an ALD process and an ALD deposition chamberthat may be used with TBTEMT during the deposition process describedherein, are further described in commonly assigned U.S. Pat. No.6,916,398, and U.S. Ser. No. 10/281,079, filed Oct. 25, 2002, andpublished as US 2003-0121608, which are herein incorporated by referencein their entirety. In another embodiment, a PE-ALD process and a PE-ALDdeposition chamber that may be used with TBTEMT during the depositionprocess described herein, are further described in commonly assignedU.S. Pat. No. 6,998,014, as well as U.S. Ser. No. 11/556,745, filed Nov.6, 2006, and published as U.S. Pub. No. 2007-0119370, and U.S. Ser. No.11/556,763, filed Nov. 6, 2006, and published as U.S. Pub. No.2007-0128864, which are herein incorporated by reference in theirentirety. A detailed description for a vaporizer or an ampoule topre-heat precursors, such as TBTEMT, is described in commonly assignedU.S. Pat. Nos. 6,905,541, 6,915,592, and 7,186,385, as well as U.S. Ser.No. 10/590,448, filed Aug. 24, 2006, and published as U.S. Pub. No.2007-0067609, and U.S. Ser. No. 11/246,890, filed Oct. 7, 2005, andpublished as U.S. Pub. No. 2007-0079759, which are herein incorporatedby reference in their entirety. A detailed description for a system todeliver the precursors, such as TBTEMT, to process chamber is describedin commonly assigned U.S. Pat. No. 6,955,211, and U.S. Ser. No.10/700,328, filed Nov. 3, 2003, and published as U.S. Pub. No.2005-0095859, which are herein incorporated by reference in theirentirety.

“Substrate surface” or “substrate,” as used herein, refers to anysubstrate or material surface formed on a substrate upon which filmprocessing is performed during a fabrication process. For example, asubstrate surface on which processing may be performed include materialssuch as monocrystalline, polycrystalline or amorphous silicon, strainedsilicon, silicon on insulator (SOI), doped silicon, silicon germanium,germanium, gallium arsenide, glass, sapphire, silicon oxide, siliconnitride, silicon oxynitride, and/or carbon doped silicon oxides, such asSiO_(x)C_(y), for example, BLACK DIAMOND® low-k dielectric, availablefrom Applied Materials, Inc., located in Santa Clara, Calif. Substratesmay have various dimensions, such as 200 mm or 300 mm diameter wafers,as well as, rectangular or square panes. Unless otherwise noted,embodiments and examples described herein are preferably conducted onsubstrates with a 200 mm diameter or a 300 mm diameter, more preferably,a 300 mm diameter. Embodiments of the processes described herein may beutilized to deposit tantalum carbide nitride materials, tantalum nitridematerials, derivatives thereof, alloys thereof, and othertantalum-containing materials on many substrates and surfaces.Substrates on which embodiments of the invention may be useful include,but are not limited to semiconductor wafers, such as crystalline silicon(e.g., Si<100> or Si<111>), silicon oxide, strained silicon, silicongermanium, doped or undoped polysilicon, doped or undoped siliconwafers, and patterned or non-patterned wafers. Substrates may be exposedto a pretreatment process to polish, etch, reduce, oxidize, hydroxylate,anneal, and/or bake the substrate surface.

EXAMPLES

Tantalum-containing materials, such as the tantalum carbide nitridematerials described herein, may be formed by the variety of depositionprocesses in the following actual and hypothetical Examples 1-11. Thedeposition of the tantalum carbide nitride materials, layers, or filmsmay be used for metal gate electrodes, barrier layers, adhesion layers,and as other components used in various Logic, Flash, and DRAMapplications, as well as in contact application.

The TBTEMT precursor may be heated in a vaporizer, a bubbler or anampoule prior to flowing into the deposition chamber. The TBTEMT may beheated to a temperature of at least about 50° C., preferably, of atleast about 60° C., more preferably, from about 65° C. to about 90° C.The preheated TBTEMT precursor is retained in the carrier gas morethoroughly than if the TBTEMT precursor was at room temperature. Anexemplary substrate temperature or substrate pedestal during thedeposition process is within a range from about 250° C. to about 600°C., preferably, from about 350° C. to about 550° C., and morepreferably, from about 400° C. to about 500° C. The deposition chamberregional varies, but has a similar temperature to that of the substratetemperature. The deposition chamber has a controlled environment that ispressurized within a range from about 1 mTorr to about 100 Torr,preferably, from about 1 Torr to about 10 Torr, and more preferably,from about 2 Torr to about 5 Torr. In other examples, it should beunderstood that other temperatures and pressures may be used during theprocess described herein.

Example 1 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 425° C. The substrate was exposed toa tantalum precursor gas at a flow rate of about 500 sccm, of which,contained about 100 sccm of TBTEMT and about 400 sccm of argon carriergas. The substrate was not exposed to a nitrogen-containing gas, such asammonia. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.75:0.31. The XPSanalysis of the tantalum carbide nitride material revealed the twodifferent binding sites for carbon, indicative to the interstitialcarbon and the elemental carbon. An interstitial/elemental carbon ratiowas deduced from the XPS spectra. Therefore, the tantalum carbidenitride material had an interstitial/elemental carbon ratio of about1.69 per XPS analysis.

Example 2 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 475° C. The substrate was exposed toa tantalum precursor gas at a flow rate of about 500 sccm, of which,contained about 100 sccm of TBTEMT and about 400 sccm of argon carriergas. The substrate was not exposed to a nitrogen-containing gas, such asammonia. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.88:0.38. Thetantalum carbide nitride material had an interstitial/elemental carbonratio of about 2.44 per XPS analysis.

Example 3 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 495° C. The substrate was exposed toa tantalum precursor gas at a flow rate of about 500 sccm, of which,contained about 100 sccm of TBTEMT and about 400 sccm of argon carriergas. The substrate was not exposed to a nitrogen-containing gas, such asammonia. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.88:0.38. Thetantalum carbide nitride material had an interstitial/elemental carbonratio of about 3.65 per XPS analysis.

Example 4 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 495° C. The substrate was exposed toammonia gas at a flow rate of about 100 sccm. The substrate was alsoexposed to a tantalum precursor gas at a flow rate of about 500 sccm, ofwhich, contained about 100 sccm of TBTEMT and about 400 sccm of argoncarrier gas. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.40:0.44.

Example 5 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 495° C. The substrate was exposed toammonia gas at a flow rate of about 500 sccm. The substrate was alsoexposed to a tantalum precursor gas at a flow rate of about 500 sccm, ofwhich, contained about 100 sccm of TBTEMT and about 400 sccm of argoncarrier gas. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.40:0.50.

Example 6 Thermal Decomposition

A tantalum carbide nitride material was deposited on a substrate by athermal decomposition process by heating the substrate and the substratepedestal to a temperature of about 495° C. The substrate was exposed toammonia gas at a flow rate of about 1,000 sccm. The substrate was alsoexposed to a tantalum precursor gas at a flow rate of about 500 sccm, ofwhich, contained about 100 sccm of TBTEMT and about 400 sccm of argoncarrier gas. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 200 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.29:0.51.

Example 7 CVD

A tantalum carbide nitride material may be deposited on a substrate by aCVD process. The substrate and the substrate pedestal were heated to atemperature of about 450° C. The substrate was simultaneously exposed toammonia gas and to a tantalum precursor gas of TBTEMT and argon forabout 35 seconds. The plasma was ignited during the full exposure. Theammonia gas had a flow rate of about 1,500 sccm and the tantalumprecursor gas had a flow rate of about 500 sccm, of which, containedabout 100 sccm of TBTEMT and about 400 sccm of argon carrier gas. Thetantalum carbide nitride material was deposited on the substrate to afinal thickness of about 150 Å. The composition analysis of the tantalumcarbide nitride material provided the respective atomic ratios oftantalum, carbon, and nitrogen to be 1.00:0.31:0.56.

Example 8 PE-CVD

A tantalum carbide nitride material may be deposited on a substrate by aPE-CVD process. The substrate and the substrate pedestal were heated toa temperature of about 490° C. The substrate was simultaneously exposedto ammonia gas and to a tantalum precursor gas of TBTEMT and argon forabout 25 seconds. The ammonia gas had a flow rate of about 1,500 sccmand the tantalum precursor gas had a flow rate of about 500 sccm, ofwhich, contained about 100 sccm of TBTEMT and about 400 sccm of argoncarrier gas. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 150 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.28:0.54.

Example 9 Pulsed-CVD

A tantalum carbide nitride material may be deposited on a substrate by apulsed-CVD process. The substrate and the substrate pedestal were heatedto a temperature of about 490° C. The substrate was sequentially exposedto ammonia gas and to a tantalum precursor gas of TBTEMT and argon. ThePE-ALD cycle exposed the substrate to the ammonia gas for about 3seconds and the tantalum precursor gas for about 2 seconds. The ammoniagas had a flow rate of about 1,500 sccm and the tantalum precursor gashad a flow rate of about 500 sccm, of which, contained about 100 sccm ofTBTEMT and about 400 sccm of argon carrier gas. The tantalum carbidenitride material was deposited on the substrate to a final thickness ofabout 130 Å. The composition analysis of the tantalum carbide nitridematerial provided the respective atomic ratios of tantalum, carbon, andnitrogen to be 1.00:0.22:0.48.

Example 10 ALD

A tantalum carbide nitride material may be deposited on a substrate byan ALD process. The substrate and the substrate pedestal were heated toa temperature of about 475° C. The substrate was sequentially exposed toammonia gas, nitrogen purge gas, a tantalum precursor gas of TBTEMT andargon, and the nitrogen purge gas during an ALD cycle. The ALD cycleexposed the substrate to the ammonia gas for about 3 seconds, thetantalum precursor gas for about 2 seconds, and the nitrogen purge gasfor about 3 seconds. The ammonia gas had a flow rate of about 1,000 sccmand the tantalum precursor gas had a flow rate of about 500 sccm, ofwhich, contained about 100 sccm of TBTEMT and about 400 sccm of argoncarrier gas. The tantalum carbide nitride material was deposited on thesubstrate to a final thickness of about 20 Å. The composition analysisof the tantalum carbide nitride material provided the respective atomicratios of tantalum, carbon, and nitrogen to be 1.00:0.25:0.53.

Example 11 PE-ALD

A tantalum carbide nitride material may be deposited on a substrate by aPE-ALD process. The substrate and the substrate pedestal were heated toa temperature of about 450° C. The substrate was sequentially exposed toammonia gas, nitrogen purge gas, a tantalum precursor gas of TBTEMT andargon, and the nitrogen purge gas during a PE-ALD cycle. The PE-ALDcycle exposed the substrate to the ammonia gas for about 3 seconds, thetantalum precursor gas for about 2 seconds, and the nitrogen purge gasfor about 3 seconds. The plasma was ignited during the ammonia exposure.The ammonia gas had a flow rate of about 1,000 sccm and the tantalumprecursor gas had a flow rate of about 500 sccm, of which, containedabout 100 sccm of TBTEMT and about 400 sccm of argon carrier gas. Thetantalum carbide nitride material was deposited on the substrate to afinal thickness of about 20 Å. The composition analysis of the tantalumcarbide nitride material provided the respective atomic ratios oftantalum, carbon, and nitrogen to be 1.00:0.26:0.50.

Although the invention has been described in terms of specificembodiments, one skilled in the art will recognize that various changesto the reaction conditions, e.g., temperature, pressure, film thicknessand the like can be substituted and are meant to be included herein andsequence of gases being deposited. For example, sequential depositionprocess may have different initial sequence. The initial sequence mayinclude exposing the substrate to the nitrogen-containing gas before thetantalum precursor gas is introduced into the processing chamber. Inaddition, the tantalum carbide nitride layer may be employed for otherfeatures of circuits in addition to functioning as a diffusion barrierfor contacts. Therefore, the scope of the invention should not be basedupon the foregoing description. Rather, the scope of the inventionshould be determined based upon the claims recited herein, including thefull scope of equivalents thereof.

While the foregoing is directed to embodiments of the invention, otherand further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for forming a tantalum-containing material on a substratesurface with a processing chamber, comprising: sequentially exposing thesubstrate surface to a nitrogen-containing gas and a process gascomprising a tantalum precursor gas and a carrier gas during an atomiclayer deposition process; and depositing a tantalum carbide nitridematerial on the substrate during the atomic layer deposition process,wherein the tantalum carbide nitride material is crystalline, andcomprises interstitial carbon and elemental carbon having aninterstitial/elemental carbon atomic ratio of about 2 or greater and thetantalum carbide nitride material having the chemical formula ofTaC_(x)N_(y), wherein x is within a range from about 0.25 to about 0.40and y is within a range from about 0.30 to about 0.50 and wherein a flowrate of the nitrogen-containing gas is adjusted to obtain theinterstitial/elemental carbon atomic ratio, wherein thenitrogen-containing gas and the process gas comprising the tantalumprecursor gas are exposed to the substrate at a gaseous flow rate ratioof at least about 1:1.
 2. The method of claim 1, wherein theinterstitial/elemental carbon atomic ratio is about 4 or greater.
 3. Themethod of claim 1, further comprising heating the substrate to atemperature within a range from about 400° C. to about 500° C.
 4. Themethod of claim 1, wherein the gaseous flow rate ratio is at least about3:1.
 5. The method of claim 4, wherein the gaseous flow rate ratio is atleast about 5:1.
 6. The method of claim 1, wherein the tantalumprecursor gas comprises an alkylamido tantalum compound and thenitrogen-containing gas comprises a gas selected from the group ofammonia, hydrazine, methyl hydrazine, dimethyl hydrazine,t-butylhydrazine, phenylhydrazine, nitrogen gas, a mixture of nitrogengas and hydrogen gas, 2,2′-azotertbutane ((CH₃)₆C₂N₂), alkyl azides,inorganic azides, and combinations thereof.
 7. The method of claim 6,wherein the nitrogen-containing gas comprises ammonia.
 8. The method ofclaim 6, wherein the alkylamido tantalum compound is selected from thegroup consisting of tertbutylimido-tris(ethylmethylamido) tantalum(TBTEMT), tertbutylimido-tris(diethylamido) tantalum (TBTDEAT),tertbutylimido-tris(dimethylamido) tantalum (TBTDMAT),tertiaryamylimido-tris(dimethylamido) tantalum (TAIMATA),tertiaryamylimido-tris(diethylamido) tantalum,tertiaryamylimido-tris(methylethylamido) tantalum,pentakis(ethylmethylamido) tantalum (PEMAT), pentakis(diethylamido)tantalum (PDEAT), pentakis(dimethylamido) tantalum (PDMAT), plasmasthereof, derivatives thereof, and combinations thereof.
 9. The method ofclaim 1, wherein the process gas further comprises a hydrocarbon gasselected from the group consisting of methane, ethane, propane, butane,ethene, acetylene, butene, butyne, plasmas thereof, derivatives thereof,and combinations thereof.
 10. A method for forming a tantalum-containingmaterial on a substrate surface within a processing chamber, comprising:sequentially exposing the substrate to one or more cycles of anitrogen-containing gas and a process gas comprising a tantalumprecursor gas and a carrier gas during a plasma enhanced atomic layerdeposition process; and depositing a tantalum carbide nitride materialon the substrate during the plasma enhanced atomic layer depositionprocess, wherein the tantalum carbide nitride material is crystalline,and comprises interstitial carbon and elemental carbon having aninterstitial/elemental carbon atomic ratio of about 2 or greater and thetantalum carbide nitride material having the chemical formula ofTaC_(x)N_(y), wherein x is within a range from about 0.25 to about 0.40and y is within a range from about 0.30 to about 0.50, and wherein thenitrogen-containing gas and the process gas comprising the tantalumprecursor gas and a carrier gas are exposed to the substrate at agaseous flow rate ratio of at least about 1:1.
 11. The method of claim10, wherein the interstitial/elemental carbon atomic ratio is about 4 orgreater.
 12. The method of claim 11, wherein a flow rate of thenitrogen-containing gas is adjusted to obtain the interstitial/elementalcarbon atomic ratio.
 13. The method of claim 10, further comprisingheating the substrate to a temperature within a range from about 400° C.to about 500° C.
 14. The method of claim 10, wherein the gaseous flowrate ratio is at least about 3:1.
 15. The method of claim 10, whereinthe tantalum precursor gas comprises an alkylamido tantalum compound andthe nitrogen-containing gas comprises a gas selected from the group ofammonia, hydrazine, methyl hydrazine, dimethyl hydrazine,t-butylhydrazine, phenylhydrazine, nitrogen gas, a mixture of nitrogengas and hydrogen gas, 2,2′-azotertbutane ((CH₃)₆C₂N₂), alkyl azides,inorganic azides, and combinations thereof.
 16. The method of claim 15,wherein the nitrogen-containing gas comprises ammonia and the alkylamidotantalum compound is selected from the group consisting oftertbutylimido-tris(ethylmethylamido) tantalum (TBTEMT),tertbutylimido-tris(diethylamido) tantalum (TBTDEAT),tertbutylimido-tris(dimethylamido) tantalum (TBTDMAT),tertiaryamylimido-tris(dimethylamido) tantalum (TAIMATA),tertiaryamylimido-tris(d iethylam ido) tantalum, tertiaryamylimido-tris(methylethylam ido) tantalum, pentakis(ethylmethylamido)tantalum (PEMAT), pentakis(diethylamido) tantalum (PDEAT),pentakis(dimethylamido) tantalum (PDMAT), plasmas thereof, derivativesthereof, and combinations thereof.
 17. The method of claim 10, whereinthe process gas further comprises a hydrocarbon gas selected from thegroup consisting of methane, ethane, propane, butane, ethene, acetylene,butene, butyne, plasmas thereof, derivatives thereof, and combinationsthereof.
 18. A method for forming a tantalum-containing material on asubstrate surface within a processing chamber, comprising: sequentiallyexposing the substrate surface to a nitrogen-containing gas and aprocess gas comprising a tantalum precursor gas and a carrier gas duringan atomic layer deposition process, wherein the nitrogen-containing gasand the process gas comprising the tantalum precursor gas and a carriergas are exposed to the substrate at a gaseous flow rate ratio of atleast about 1:1; and depositing a tantalum carbide nitride material onthe substrate during the atomic layer deposition process, wherein thetantalum carbide nitride material is crystalline, and comprisesinterstitial carbon and elemental carbon having aninterstitial/elemental carbon atomic ratio of about 2 or greater and thetantalum carbide nitride material having the chemical formula ofTaC_(x)N_(y), wherein x is within a range from about 0.20 to about 0.50and y is within a range from about 0.20 to about 0.55 and wherein a flowrate of the nitrogen-containing gas is adjusted to obtain theinterstitial/elemental carbon atomic ratio.
 19. The method of claim 18,the tantalum carbide nitride material having the chemical formula ofTaC_(x)N_(y), wherein x is within a range from about 0.25 to about 0.40and y is within a range from about 0.30 to about 0.5, wherein a flowrate of the nitrogen-containing gas is adjusted to obtain theinterstitial/elemental carbon atomic ratio.